On Sun, Sep 18, 2011 at 12:59 PM, Nathan Edgars II <[email protected]> wrote: > On 9/18/2011 12:54 PM, Anthony wrote: >> >> On Sun, Sep 18, 2011 at 12:01 PM, Dave F.<[email protected]> wrote: >>> >>> On 18/09/2011 16:20, Nathan Edgars II wrote: >>>> >>>> Here's an example of what tagging every lane would lead to: >>>> http://wiki.openstreetmap.org/wiki/File:Silly_lane_count.jpg >>> >>> I see nothing intrinsically wrong with that. Lots of splitting ways& >>> tagging admittedly, but that's a problem with OSM& its tagging process. >> >> I agree. This data would be quite useful to routing software, >> especially when combined with information about which lanes have which >> turn restrictions. > > I think to do this properly you'd have to map every lane as a separate way.
Properly or perfectly? You can get a lot of information from just the number of lanes and the turn restrictions on each. Enough for a router to say "stay in one of the left two lanes". Yes, mapping every lane as a separate way would be even better, but let's go one step at a time. >> Yes, it's a lot of work, and people routinely ignore it, but that >> doesn't make it wrong. The way I see it, ignoring short lane number >> changes is equivalent to ignoring short traffic dividers (e.g. >> http://g.co/maps/cqdmf). I wouldn't blame someone for ignoring it, >> but I wouldn't blame someone for including it either. > > I see it as more like ignoring short breaks in traffic dividers (like when > crossing a divided highway). Intersections have their own set of problems. I'm referring here to changes in the number of lanes which are not located within an intersection. >> Nathan, what is one supposed to do if *all* lanes are turning lanes >> (e.g. http://g.co/maps/4j2uh)? Do we tag it lanes=0? > > I would use lanes=2 there, since that's how many through lanes there are > before the turn lanes begin. And you think any other number of lanes would be *wrong*? I might lanes=2 here myself. But I'd recognize that, in doing so, my mapping was incomplete. _______________________________________________ Tagging mailing list [email protected] http://lists.openstreetmap.org/listinfo/tagging
